1. Technical Field
The present invention relates to a power output apparatus that outputs power to a driveshaft, a vehicle equipped with the power output apparatus, and a control method of the power output apparatus.
2. Description of the Related Art
One proposed configuration of a power output apparatus uses an oxygen concentration sensor that is located in an exhaust conduit of an engine to measure the oxygen concentration in exhaust emission from the engine (see, for example, Japanese Patent Laid-Open Gazette No. H10-212999). The proposed power output apparatus increases the power supply to a heater of the oxygen concentration sensor and raises the voltage applied to a sensor element in response to a fuel cut operation of the engine during deceleration. An output signal of the oxygen concentration sensor under the condition that an integrated value of exhaust flow rate since the start of the fuel cut condition reaches or exceeds a preset reference level is set to a reference value of the oxygen concentration sensor. The output signal of the oxygen concentration sensor is corrected according to the temperature of the sensor element and the pressure of the exhaust emission. A failure of the oxygen concentration sensor is detected, based on a result of comparison between the corrected output signal and a preset failure detection value.